Which word and letter have different (不同的) pronunciations?

Which word of the following has a different stress from the others?
A. expert          B. except        C. expect

Do you know why you sleep? You may think it’s because you’re tired. Or perhaps you’ve been told sleep is good for you. Yet no one knows exactly why or how people sleep.
Until the early 1950s, most scientists thought the body and brain rested during sleep. Then a scientist watched people sleep. He noticed that during periods of between 5 and 30 minutes each, sleepers’ eyes made rapid movements, as if they were watching something. He called these periods REM sleep, for Rapid Eye Movement. Periods when sleepers’ eyes did not move he called non-REM sleep.
Whenever the scientist woke people during REM sleep, they were having vivid dreams. Measurements showed that sleepers’ pulses（脉搏）went up quickly during REM sleep. Their breathing, heartbeat, and the blood going to the brain also increased. Far from being a time of rest, REM sleep is a time when the body is hard at work. Scientists still don’t know the reason for this. Some believe REM sleep makes learning easier. Babies spend a lot of time in REM sleep. Because of this, some scientists believe that REM sleep helps the brain grow. Others think REM sleep is a time for the brain to empty the day’s garbage.
One thing all the scientists agree on is that sleep is necessary. Without enough sleep, people make mistakes. Most major car accidents happen during the early morning hours, when people are sleepiest.
【小题1】During REM sleep, a person’s breathing and heartbeat ________.

When I was ten, my mother worked all day so I had to take care of my younger brother. At that time my little brother was about four years old and he missed mum all the time.

One day, after I had given him his dinner, he started crying for mum. He was so young and really needed mum. So I dressed him, put on his shoes, carried him on my back and walked out. Soon he fell asleep. About half an hour later, I found that he had lost a shoe while sleeping. I took him off my back and put him down. I knew we needed to find that shoe, for our mother couldn’t afford new shoes. We had to go back to find it, so I told my brother to wait right there. A man heard it and stopped me just before I walked off. He asked me, “You are leaving your brother here to find the shoe? What would you do if he is not here when you return?” I did not know how to answer that question. He continued, “It’s OK if you can’t find the shoe, but it is not OK to lose your brother.” Then he sent us to mum’s workplace by taxi.

My whole life I have depended on the kindness of many strangers, I feel regretful that I cannot find them and say thank you. I do not even remember what the man’s face looked like, but he taught me a lesson—people are more important than things.

1. Why did the younger brother cry for his mother?

A. Because he was hungry.               B. Because he missed his mother. 

C. Because he wanted to sleep.          D. Because he wanted to play outside.

2.What does the underlined word “regretful” in the last paragraph mean?

A. Sorry.           B. Happy.           C. Excited.             D. Angry.

3.What did the man mean by saying “It’s OK if you can’t find the shoe, but it is not OK to lose your brother.”?

A. People are more important than things.

B. Things are more important than people.

C. Both the shoe and your brother are important.

D. The shoe is more important than your brother.

4.According to the passage, which word can best describe the man?

A. Rude.            B. Funny.           C. Silly.               D. Kind.